For mobile communication, communications terminals which are connected to a line-bound communication network by means of a radio link are frequently used. Examples of such arrangements are the known mobile radio networks, for example the GSM network, private telephone networks (DECT arrangements), WLAN arrangements etc. All these arrangements have in common the fact that bidirectional data streams in which useful data (audio data, video data etc.) is transmitted are used for the communication between one or more base stations (access point) and the mobile communications terminals (mobile telephones, cordless telephones, PDAs, multimedia PCs etc.).